This study examined the relationship between mature phase of the cold event in 1999 and the East Asian summer atmosphere circulation in 2000.The cold event reaches its mature phase in the autumn and winter of 1999,whi...This study examined the relationship between mature phase of the cold event in 1999 and the East Asian summer atmosphere circulation in 2000.The cold event reaches its mature phase in the autumn and winter of 1999,which is the strongest La Nina episode in recent 11 years.There is a clear anomalous pattern of the atmosphere circulation around East Asia in the summer of 2000, i.e.the negative anomaly centers around the Cherski Mountains and 20°N,170°E at 500 hPa,the main body of the subtropical high keeps in further northern position than usual and the negative anomaly of precipitation located in southern central China.This pattern is thought as the response to the preceding strong cold event in autumn of 1999.It is also identified that the response of the East Asian atmosphere circulation in summer of 2000 to the strong La Nina event in 1999 belongs to the top rank in recent 43 years.On the other hand,the inactive blocking anticyclone around East Asia in summer of 2000 is associated with the positive SST anomaly and the 850 hPa temperature anomaly around the Bering Sea simultaneously.Nevertheless,although the impact on the summer atmosphere circulation around East Asia from La Nina events could not rank with that from E1 Nino,the impact could not be neglected especially in a strong La Nina case.展开更多
This study has reviewed recent studies about impact of the Rossby wave propagation on the weather of East Asia.Then,we have focused on the northward progression of the subtropical high affected by the propagations and...This study has reviewed recent studies about impact of the Rossby wave propagation on the weather of East Asia.Then,we have focused on the northward progression of the subtropical high affected by the propagations and their interaction.The following results are obtained:(1)The two kinds of meridional Rossby wave propagations often affect the East Asian weather in summer, which propagate in two conflicting directions(northwest-southeastward and southwest-northeast- ward).This is considered as the interaction of the large-scale systems between high and low latitudes with wave propagation,especially to the circulation systems around East Asia.(2)The northward progression of the subtropical high is largely restrained,aecompanied by the southward shift of the convective activity in middle latitudes,under the strong and persistent Rossby wave propagation from high to low latitudes.And the opposite role could be found in the Rossby wave propagation from low to high latitudes.展开更多
基金supported by the program by Minstry of Science and Technology of China(No.2002DIB20067)
文摘This study examined the relationship between mature phase of the cold event in 1999 and the East Asian summer atmosphere circulation in 2000.The cold event reaches its mature phase in the autumn and winter of 1999,which is the strongest La Nina episode in recent 11 years.There is a clear anomalous pattern of the atmosphere circulation around East Asia in the summer of 2000, i.e.the negative anomaly centers around the Cherski Mountains and 20°N,170°E at 500 hPa,the main body of the subtropical high keeps in further northern position than usual and the negative anomaly of precipitation located in southern central China.This pattern is thought as the response to the preceding strong cold event in autumn of 1999.It is also identified that the response of the East Asian atmosphere circulation in summer of 2000 to the strong La Nina event in 1999 belongs to the top rank in recent 43 years.On the other hand,the inactive blocking anticyclone around East Asia in summer of 2000 is associated with the positive SST anomaly and the 850 hPa temperature anomaly around the Bering Sea simultaneously.Nevertheless,although the impact on the summer atmosphere circulation around East Asia from La Nina events could not rank with that from E1 Nino,the impact could not be neglected especially in a strong La Nina case.
基金the National Natural Science Foundation of China under Grant No.49794030Ministry of Science and Technology of China(G1998040908).
文摘This study has reviewed recent studies about impact of the Rossby wave propagation on the weather of East Asia.Then,we have focused on the northward progression of the subtropical high affected by the propagations and their interaction.The following results are obtained:(1)The two kinds of meridional Rossby wave propagations often affect the East Asian weather in summer, which propagate in two conflicting directions(northwest-southeastward and southwest-northeast- ward).This is considered as the interaction of the large-scale systems between high and low latitudes with wave propagation,especially to the circulation systems around East Asia.(2)The northward progression of the subtropical high is largely restrained,aecompanied by the southward shift of the convective activity in middle latitudes,under the strong and persistent Rossby wave propagation from high to low latitudes.And the opposite role could be found in the Rossby wave propagation from low to high latitudes.
