Teleconnection Mode between the Tropical Pacific－Indian Ocean Temperature Anomaly and Southern Hemisphere Tropospheric Circulation and Its Mechanism

The teleconnection mode between the tropical Pacific－Indian Ocean temperature anomaly and Southern Hemisphere tropospheric circulation and its mechanism are studied through NOAA SST and NCEP/NCAR reanalysis data sets. First of all, spatial teleconnection mode is presented by using correlation and composition analyses and results show that there are obvious characteristics of remote response in the Southern Hemisphere troposphere closely related with the tropical Pacific－Indian Ocean temperature anomaly in boreal autumn and winter. These centers of action compose a Rossby wave train, starting from the middle of the tropical Pacific and ending in southern Africa and the tropical Indian Ocean. The train links the tropical Pacific, the Indian Ocean to the Southern Hemisphere high latitudes and plays a similar “atmosphere bridge” role. However, the pure IOD (Indian Ocean Dipole) and pure ENSO are difficult to excite teleconnection wave train in the Southern Hemisphere, which further confirms the interaction between them. Secondly, the theory of planetary wave energy propagation can be used to explain the teleconnection. It is found that the energy propagation of planetary wave with zonal numbers 1－3 is the possible mechanism for the teleconnection between the tropical Pacific－Indian Ocean temperature anomaly and the Southern Hemisphere tropospheric circulation.