Early theoretical analyses indicated that the tropics and extratropics are relatively independent due to the existence of critical latitudes.However,considerable observational evidence has shown that a clear dynamical...Early theoretical analyses indicated that the tropics and extratropics are relatively independent due to the existence of critical latitudes.However,considerable observational evidence has shown that a clear dynamical link exists between the tropics and midlatitudes.To better understand such atmospheric teleconnection,several theories of wave energy propagation are reviewed in this paper：（1） great circle theory,which reveals the characteristics of Rossby waves propagating in the spherical atmosphere;（2） westerly duct theory,which suggests a ＂corridor＂ through which the midlatitude disturbances in one hemisphere can propagate into the other hemisphere;（3） energy accumulation-wave emanation theory,which proposes processes through which tropical disturbances can affect the atmospheric motion in higher latitudes;（4） equatorial wave expansion theory,which further explains the physical mechanisms involved in the interaction between the tropics and extratropics;and（5） meridional basic flow theory,which argues that stationary waves can propagate across the tropical easterlies under certain conditions.In addition,the progress made in diagnosing wave-flow interaction,particularly for Rossby waves,inertial-gravity waves,and Kelvin waves,is also reviewed.The meridional propagation of atmospheric energy exhibits significant annual and interannual variations,closely related to ENSO and variation in the westerly jets and tropical upper-tropospheric troughs,amongst others.展开更多
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2014CB953900)National Natural Science Foundation of China(41375081)+1 种基金LASW State Key Laboratory Special Fund(2013LASW-A05)China Meteorological Administration Special Public Welfare Research Fund(GYHY201406018)
文摘Early theoretical analyses indicated that the tropics and extratropics are relatively independent due to the existence of critical latitudes.However,considerable observational evidence has shown that a clear dynamical link exists between the tropics and midlatitudes.To better understand such atmospheric teleconnection,several theories of wave energy propagation are reviewed in this paper：（1） great circle theory,which reveals the characteristics of Rossby waves propagating in the spherical atmosphere;（2） westerly duct theory,which suggests a ＂corridor＂ through which the midlatitude disturbances in one hemisphere can propagate into the other hemisphere;（3） energy accumulation-wave emanation theory,which proposes processes through which tropical disturbances can affect the atmospheric motion in higher latitudes;（4） equatorial wave expansion theory,which further explains the physical mechanisms involved in the interaction between the tropics and extratropics;and（5） meridional basic flow theory,which argues that stationary waves can propagate across the tropical easterlies under certain conditions.In addition,the progress made in diagnosing wave-flow interaction,particularly for Rossby waves,inertial-gravity waves,and Kelvin waves,is also reviewed.The meridional propagation of atmospheric energy exhibits significant annual and interannual variations,closely related to ENSO and variation in the westerly jets and tropical upper-tropospheric troughs,amongst others.
