scholarly journals Impacts of Spatiotemporal Anomalies of Tibetan Plateau Snow Cover on Summer Precipitation in Eastern China

2017 ◽  
Vol 30 (3) ◽  
pp. 885-903 ◽  
Author(s):  
Chenghai Wang ◽  
Kai Yang ◽  
Yiling Li ◽  
Di Wu ◽  
Yue Bo
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
River Basin ◽  
Yangtze River ◽  
Southern China ◽  
Yangtze River Basin ◽  
Eastern China ◽  
Summer Precipitation ◽  
The Yangtze River ◽  
The Yangtze River Basin

Abstract Tibetan Plateau (TP) snow cover undergoes significant temporal and spatial variations during the winter and spring months. This study investigates the relationship between the spatiotemporal distribution of winter–spring snow cover (SC) over the TP and summer precipitation in eastern China (EC) using the singular value decomposition (SVD) method. Four simulation experiments are designed to validate the results of SVD analysis. Both observations and simulations show that heavier snow cover in the southern TP leads to more rainfall in the Yangtze River basin and northeastern China, and less precipitation in southern China, whereas heavier snow cover in the northern TP results in enhanced rainfall in southeastern and northern China and weakened precipitation in the Yangtze River basin. The linkage is attributed to anomalous westerly winds in the upper troposphere at around 200 hPa and to changes of the southern branch of westerlies at 500 hPa on the south side of the TP, which are caused by lasting diabatic heat anomalies over the TP. The shifts in position of the westerly jet at the exit region and negative anomalies of geopotential height at 500 hPa further result in anomalous anticyclone over the East China Sea and the corresponding 850-hPa water vapor convergence and influence the anomalous summer precipitation belt in EC.

scholarly journals Summer Drought Patterns in the Middle-Lower Reaches of the Yangtze River Basin and Their Connections with Atmospheric Circulation before and after 1980

2016 ◽  
Vol 2016 ◽  
pp. 1-18
Author(s):  
Shuping Li ◽  
Guolin Feng ◽  
Wei Hou
Keyword(s):  
River Basin ◽  
Moisture Transport ◽  
Yangtze River ◽  
Southern China ◽  
Yangtze River Basin ◽  
Summer Drought ◽  
The Yangtze River ◽  
Before And After ◽  
Drought Pattern ◽  
The Yangtze River Basin

The three summer drought patterns of the middle-lower reaches of the Yangtze River basin (MLRYRB) and their associated atmospheric circulation were investigated before and after 1980. For the whole-basin wide drought pattern during 1961–1979, the anomalous high ridge over Japan blocked the northerly flow from Siberia to southern China. Further, the western Pacific subtropical high (WPSH) was weaker than normal and shifted eastward. For the southern drought and northern flood pattern during 1961–1979, the zonal circulation was straight and an anomalous anticyclonic circulation was located over Japan. Less moisture was transported to southern China associated with the weakened WPSH. During 1980–2013, the WPSH extended westward and controlled the southern part of the MLRYRB, and an anomalous cyclonic circulation was centered over Japan. For the southern flood and northern drought pattern during 1961–1979, the meridional circulation was obvious, and the WPSH was weaker than normal. The anomalous southwesterly moisture transport appeared to southern China. However, during 1980–2013 the continental high pressure impacted northern China. The WPSH shifted eastward and the anomalous northeasterly moisture transport presented over eastern China.

scholarly journals Extratropical Factors Affecting the Variability in Summer Precipitation over the Yangtze River Basin, China

2017 ◽  
Vol 30 (20) ◽  
pp. 8357-8374 ◽  
Author(s):  
Xinyu Li ◽  
Riyu Lu
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Lower Troposphere ◽  
Summer Precipitation ◽  
Physical Factors ◽  
The Yangtze River ◽  
The South ◽  
The North ◽  
The Yangtze River Basin

Abstract The Yangtze River basin (YRB), a typical East Asian monsoon region, experiences a large year-to-year variability in summer precipitation and is subject to both floods and droughts. There is a well-known seesaw relationship in precipitation between the tropical western North Pacific and the YRB, but more than half of the variance in precipitation in the YRB cannot be explained by this seesaw pattern. The authors therefore investigated other physical factors that might affect precipitation in the YRB. The results indicate that the northeasterly anomaly in the lower troposphere to the north of the YRB plays an important role in the variability in precipitation. This northeasterly anomaly is paired with the southwesterly anomaly to the south of the YRB. They both play an important role in water vapor accumulation over the YRB and intensify the meridional gradient of the equivalent potential temperature θe over the YRB by bringing dry and cool air from the north and wet air from the south. This intensified θe gradient favors convective instability and heavier rainfall in the YRB, as previous studies on mei-yu weather have indicated. Furthermore, it is found that the zonally oriented teleconnection along the Asian westerly jet and the meridional displacement of the jet can affect circulation in the lower troposphere and precipitation in the YRB. These results highlight the role of extratropical circulation anomalies and thus contribute to a more comprehensive understanding of the variability of precipitation in the YRB.

scholarly journals Interdecadal Change in the Effect of Spring Soil Moisture over the Indo-China Peninsula on the Following Summer Precipitation over the Yangtze River Basin

2020 ◽  
Vol 33 (16) ◽  
pp. 7063-7082
Author(s):  
Chujie Gao ◽  
Gen Li ◽  
Haishan Chen ◽  
Hong Yan
Keyword(s):  
Soil Moisture ◽  
River Basin ◽  
Summer Monsoon ◽  
Land Surface ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Summer Precipitation ◽  
Interdecadal Change ◽  
The Yangtze River ◽  
The Yangtze River Basin

AbstractThe land surface energy exchange over the Indo-China Peninsula (ICP) is important for regulating regional weather and climate. This work investigates the effect of spring soil moisture (SM) over the ICP on the following summer precipitation over the Yangtze River basin (YRB) during 1961–2010. The results show that the spring SM over the ICP has a significant negative correlation with the following summer YRB precipitation. However, this relationship experiences an obvious interdecadal change with a much stronger correlation in the epoch before the early 1990s (1961–91) than in the later decades (1992–2010). In spring, an abnormally lower SM over the ICP could induce less surface evapotranspiration, increasing local temperature until the summer. Before the 1990s, the resultant anomalous ICP heating raises the local geopotential height, resulting in an excessive westward extension of the western Pacific subtropical high (WPSH). Accordingly, the enhanced southwesterly summer monsoon would transport more moisture to the YRB, intensifying the mei-yu front and local precipitation. In the early 1990s, the East Asian summer monsoon underwent an abrupt change with an interdecadal westward extension of the climatic WPSH. Consequently, the similar abnormal ICP surface heating induced by the anomalous SM would have different influences on the monsoonal circulation, causing a much weaker effect on the YRB precipitation in the recent decades.

Effects of convection over the Tibetan Plateau on rainstorms downstream of the Yangtze River Basin

2019 ◽  
Vol 219 ◽  
pp. 24-35 ◽  
Author(s):  
Yang Zhao ◽  
Xiangde Xu ◽  
Liping Liu ◽  
Rong Zhang ◽  
Hongxiong Xu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
The Tibetan Plateau ◽  
The Yangtze River ◽  
The Yangtze River Basin
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