Recent studies show that a combination mode (C-mode) represents the seasonally modulated dynamics of ENSO, which plays an important role in maintaining the western North Pacific anomalous anticyclone. This C-mode coul...Recent studies show that a combination mode (C-mode) represents the seasonally modulated dynamics of ENSO, which plays an important role in maintaining the western North Pacific anomalous anticyclone. This C-mode could obviously influence the East Asian climate, especially since the contribution of ENSO to southern China's precipitation has weakened since the late 1990s. This paper evaluates whether the C-mode and its influences on precipitation over southern China can be realistically described by the climate model ECHAM5/MPI-OM. The authors find that the model is able to reproduce the spatial and temporal variability of the C-mode and the asymmetric responses of air-sea variations in the tropical Pacific. The model also reveals the observed significant effects of the C-mode on the wintertime and springtime rainfall over southern China during El Nino events. The findings have implications for ECHAM5/MPI-OM being a valuable tool for simulating and predicting the C-mode-related seasonal precipitation over southern China.展开更多
In this study,the relationship between the North Atlantic Oscillation （NAO） in winter （DecemberFebruary） and the precipitation over southem China （SCP） in the following spring （March-May） was investigated.Resu...In this study,the relationship between the North Atlantic Oscillation （NAO） in winter （DecemberFebruary） and the precipitation over southem China （SCP） in the following spring （March-May） was investigated.Results showed an interdecadal change,from strong to weak connection,in their connection.Before the early 1980s,they were highly correlated,with a strong （weak） winter NAO followed by an increased （decreased） spring SCP.However,after the early 1980s,their relationship was weakened significantly.This unstable relationship may be linked to the climatological change of East Asian jet.Before the early 1980s,the wave train along the Asian jet propagated the NAO signal eastward to East Asia and affected local upper-tropospheric atmospheric circulation.A strong NAO in winter led to an anomalous anticyclonic circulation at the south side of 30°N in East Asia in spring,resulting in an increase of SCP.In contrast,after the early 1980s,the wave train pattern along the Asian jet extended eastward due to strengthening of the climatological East Asian jet.Correspondingly,the NAO-related East Asian atmospheric circulations in the upper troposphere shifted eastward,thereby weakening the linkage between the spring SCP and the winter NAO.展开更多
基金supported by the National Key R&D Programme of China [grant number 2017YFA0604201]the National Natural Science Foundation of China [grant numbers 41576019 and 41876012]
文摘Recent studies show that a combination mode (C-mode) represents the seasonally modulated dynamics of ENSO, which plays an important role in maintaining the western North Pacific anomalous anticyclone. This C-mode could obviously influence the East Asian climate, especially since the contribution of ENSO to southern China's precipitation has weakened since the late 1990s. This paper evaluates whether the C-mode and its influences on precipitation over southern China can be realistically described by the climate model ECHAM5/MPI-OM. The authors find that the model is able to reproduce the spatial and temporal variability of the C-mode and the asymmetric responses of air-sea variations in the tropical Pacific. The model also reveals the observed significant effects of the C-mode on the wintertime and springtime rainfall over southern China during El Nino events. The findings have implications for ECHAM5/MPI-OM being a valuable tool for simulating and predicting the C-mode-related seasonal precipitation over southern China.
基金supported by the Special Fund for Public Welfare Industry (Meteorology) (GYHY201306026)the National Natural Science Foundation of China (41275078)the National Basic Research Program of China (2009CB421407)
文摘In this study,the relationship between the North Atlantic Oscillation （NAO） in winter （DecemberFebruary） and the precipitation over southem China （SCP） in the following spring （March-May） was investigated.Results showed an interdecadal change,from strong to weak connection,in their connection.Before the early 1980s,they were highly correlated,with a strong （weak） winter NAO followed by an increased （decreased） spring SCP.However,after the early 1980s,their relationship was weakened significantly.This unstable relationship may be linked to the climatological change of East Asian jet.Before the early 1980s,the wave train along the Asian jet propagated the NAO signal eastward to East Asia and affected local upper-tropospheric atmospheric circulation.A strong NAO in winter led to an anomalous anticyclonic circulation at the south side of 30°N in East Asia in spring,resulting in an increase of SCP.In contrast,after the early 1980s,the wave train pattern along the Asian jet extended eastward due to strengthening of the climatological East Asian jet.Correspondingly,the NAO-related East Asian atmospheric circulations in the upper troposphere shifted eastward,thereby weakening the linkage between the spring SCP and the winter NAO.
