scholarly journals Contribution of large-scale circulation anomalies to variability of summer precipitation extremes in northeast China

2018 ◽  
Vol 19 (12) ◽  
pp. e867 ◽  
Author(s):  
Fuqiang Cao ◽  
Tao Gao ◽  
Li Dan ◽  
Zhuguo Ma ◽  
Xiujing Yang ◽  
...  
Keyword(s):  
Northeast China ◽  
Large Scale ◽  
Summer Precipitation ◽  
Precipitation Extremes ◽  
Large Scale Circulation ◽  
Circulation Anomalies

Large-Scale Circulation Anomalies Associated with Extreme Heat in South Korea and Southern–Central Japan

2020 ◽  
Author(s):  
Ke Xu
Keyword(s):  
South Korea ◽  
East Asia ◽  
Large Scale ◽  
Extreme Heat ◽  
Central Japan ◽  
Large Scale Circulation ◽  
Westerly Jet ◽  
Anomalous Anticyclone ◽  
Wave Trains ◽  
Circulation Anomalies

<p>    The large-scale circulation anomalies associated with extreme heat (EH) in South Korea and southern–central Japan are examined using data during the time period 1979–2016. Statistical analysis indicates that EH days in these two regions are concentrated in July and August and tend to occur simultaneously. These EH days are therefore combined to explore the physical mechanisms leading to their occurrence. The composite results indicate that the anomalous atmospheric warming during EH days is dominantly caused by a significant subsidence anomaly, which is associated with a deep anomalous anticyclone over East Asia. Further investigation of the evolution of circulation anomalies suggests that the anomalous anticyclone over East Asia related to EH is primarily initiated by wave trains originating from upstream regions, which propagate eastward along the Asian westerly jet in the upper troposphere. These wave trains can be categorized into two types that are characterized by the precursor anticyclonic and cyclonic anomalies, respectively, over central Asia. The distinction between these two types of wave train can be explained by the wavenumbers of the Rossby waves, which are modulated by both the intensity and the shape of the Asian westerly jet as the background basic flow.</p>

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