scholarly journals An interdecadal shift in the number of hot nights around 1997 over Eastern China

2016 ◽  
Vol 17 (9) ◽  
pp. 501-509
Author(s):  
Sisi Chen ◽  
Jingyong Zhang ◽  
Gang Huang
2013 ◽  
Vol 13 (24) ◽  
pp. 12433-12450 ◽  
Author(s):  
T. Wang ◽  
H. J. Wang ◽  
O. H. Otterå ◽  
Y. Q. Gao ◽  
L. L. Suo ◽  
...  

Abstract. Observation shows that eastern China experienced an interdecadal shift in the summer precipitation during the second half of the 20th century. The summer precipitation increased in the middle and lower reaches of the Yangtze River valley, whereas it decreased in northern China. Here we use a coupled ocean–atmosphere general circulation model and multi-ensemble simulations to show that the interdecadal shift is mainly caused by the anthropogenic forcing. The rapidly increasing greenhouse gases induce a notable Indian Ocean warming, causing a westward shift of the western Pacific subtropical high (WPSH) and a southward displacement of the East Asia westerly jet (EAJ) on an interdecadal timescale, leading to more precipitation in Yangtze River valley. At the same time the surface cooling effects from the stronger convection, higher precipitation and rapidly increasing anthropogenic aerosols contribute to a reduced summer land–sea thermal contrast. Due to the changes in the WPSH, the EAJ and the land–sea thermal contrast, the East Asian summer monsoon weakened resulting in drought in northern China. Consequently, an anomalous precipitation pattern started to emerge over eastern China in the late 1970s. According to the model, the natural forcing played an opposite role in regulating the changes in WPSH and EAJ, and postponed the anthropogenically forced climate changes in eastern China. The Indian Ocean sea surface temperature is crucial to the response, and acts as a bridge to link the external forcings and East Asian summer climate together on a decadal and longer timescales. Our results further highlight the dominant roles of anthropogenic forcing agents in shaping interdecadal changes of the East Asian climate during the second half of the 20th century.


2013 ◽  
Vol 13 (5) ◽  
pp. 11997-12032 ◽  
Author(s):  
T. Wang ◽  
H. J. Wang ◽  
O. H. Otterå ◽  
Y. Q. Gao ◽  
L. L. Suo ◽  
...  

Abstract. Observation shows that eastern China has experienced an interdecadal shift in the summer precipitation during the second half of the 20th century. The summer precipitation increased in the middle and lower reaches of the Yangtze River Valley, whereas it decreased in northern China. Here we use a coupled ocean–atmosphere general circulation model and multi-ensemble simulations to show that the interdecadal shift is mainly caused by the combined effect of increasing global greenhouse gases and regional aerosol emissions over China. The rapidly increasing greenhouse gases induce tropical warming and a westward shift of the western Pacific subtropical high, leading to more precipitation in Yangtze River Valley. At the same time the aerosol cooling effect over land contributes to a reduced summer land–sea thermal contrast and therefore to a weakened East Asian summer monsoon and to drought in northern China. Consequently, an anomalous precipitation pattern starts to emerge in eastern China in late 1970s. Our results highlight the important role of anthropogenic forcing agents in shaping the weakened East Asian summer monsoon and associated anomalous precipitation in eastern China.


2021 ◽  
pp. 1-46
Author(s):  
Yuntao Jian ◽  
Marco Y. T. Leung ◽  
Wen Zhou ◽  
Maoqiu Jian ◽  
Song Yang ◽  
...  

AbstractIn this study, the interdecadal variability of the relationship between ENSO and winter synoptic temperature variability (STV) over the Asian-Pacific-American region is investigated based on observational data from 1951 to 2018. An interdecadal shift in the ENSO-STV relationship occurred in the 1980s over Eastern China, changing from significant in Period 1 (P1, 1951-1987) to insignificant in Period 2 (P2, 1988-2018). But the ENSO-STV relationship is significantly stable over North America for the whole period. In addition, a possible reason for this interdecadal shift in the ENSO-STV relationship over Eastern China is also investigated. During P1, the ENSO pattern is significantly correlated to the temperature gradient over Northeast Asia, which is the key region influencing the intensification of extratropical eddies. The intensification of extratropical eddies over Northeast Asia is directly associated with the magnitude of STV over Eastern China. But in P2, the ENSO pattern is not related to the temperature over Northeast Asia. Therefore, the change in the ENSO pattern from P1 to P2 contributes to the interdecadal shift in the ENSO-STV relationship in the 1980s over Eastern China by influencing the temperature gradient over Northeast Asia, while ENSO can influence the temperature gradient over North America for the whole period. Furthermore, the possible role of the ENSO patterns in P1 and P2 is also examined by using an atmospheric general circulation model, highlighting that the pattern of SST variation is a determining factor in regulating STV in different regions.


2021 ◽  
Author(s):  
Chao Zhang ◽  
Yuanyuan Guo ◽  
Zhiping Wen

Abstract Previous works extensively investigated the influences of the winter-spring Tibetan Plateau snow cover (TP, TPSC) on climate variability over the East Asia. The present work documents an interdecadal-changed impacts of different spring TPSC anomaly (TPSCA) patterns on spring precipitation over eastern China (SPEC) around the early 1990s. It is found that the correlation of eastern and western TPSCA shifts from negative to positive around 1990. The empirical orthogonal function (EOF) analysis applying onto the spring TPSCA during 1970–1989 (P1) and during 1991–2017 (P2) adds additional support for such interdecadal change in the relationship between the eastern and western TPSCA. Specifically, the leading EOF (EOF1) mode in P1 shows an out-of-phase pattern with opposite signals lying over the eastern and western TP, while the counterpart in P2 is characterized by an in-phase pattern over the entire TP. Corresponding to more (less) snow cover in the eastern (western) TP in P1, a significant TP cold cyclone (TPCC) and a downstream anticyclone over the western North Pacific are observed. Anomalous southerly flow prevailing east to TPCC could bring the warm-wet air from tropics to the coast of East Asian, which largely enhances the spring precipitation south to Yangtze River Valley (YRV). By contrast, regarding more snow cover both in the eastern and western TP in P2, a relatively northward-displaced and wider TPCC sweeps over the entire TP compared with the TPSC-induced TPCC in P1. Moreover, there are significant sinking anomalies observed in the downstream YRV-HRV region, which leads to suppressed spring precipitation over there via the dry-cold advection process. Hence, these discrepancies of local and downstream atmospheric circulation induced by the out-of-phase and in-phase TPSCA patterns in two epochs play an important role in resulting in the interdecadal shift of the SPEC anomaly pattern around 1990.


2019 ◽  
Vol 79 (2) ◽  
pp. 109-126
Author(s):  
D Tian ◽  
J Su ◽  
F Zhou ◽  
B Mayer ◽  
D Sein ◽  
...  

2013 ◽  
Vol 20 (2) ◽  
pp. 159-167
Author(s):  
Xie Yubin ◽  
Ma Zunping ◽  
Yang Qingsong ◽  
Fang Xiaofeng ◽  
Zhang Zhiguo ◽  
...  

2010 ◽  
Vol 32 (4) ◽  
pp. 998-1002
Author(s):  
Bi-yang Wen ◽  
Zi-li Li ◽  
Hao Zhou ◽  
Zhen-hua Shi ◽  
Shi-cai Wu ◽  
...  

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