Analysis for Interannual Variability of Heat Content Anomaly in the Upper Tropical Indian Ocean

The monthly thermohaline data (1950~2006) from Japan Meteorological Agency are used to analyse the interannual spatial and temporal characteristics of the tropical Indian Ocean heat content anomaly field, and to discuss its relationships respectively with ENSO, the Indian Ocean Dipole(IOD) , the Southern Indian Ocean Dipole(SIOD) , and the tropical Indian Ocean zonal wind anomalies. The results show that the interannual oscillation of the tropical Indian Ocean heat content anomalies is comprised of two main modes with spatial structures different from each other and 2~6 year period similar to each other, but the second mode would be rather like the early development stage of the first mode. The interannual oscillation of the tropical Indian Ocean heat content anomalies may 1～9 months lead the ENSO cycle and 3-11 months lead the IOD variation, but about 2 months lag behind the SIOD variation. The equatorial Indian Ocean zonal wind anomaly is one of the important factors effecting on the interannual oscillation of the tropical Indian Ocean heat content.