基于历史表层漂流浮标数据,利用轨迹跟踪方法分析了南印度洋表层副热带环流的平均态特性.浮标路径反映出南印度洋海水由高纬向低纬输运的过程大体可分为2种:海水沿南印度洋东边界北上,汇入南赤道流后绕过马达加斯加岛北侧,沿非洲东岸跨越赤道进入北半球;或者由南印度洋中部北上,受南赤道流影响转向,到达马达加斯加岛东部后返回南印度洋构成副热带环流.漂流浮标获得的流速和能量结果表明,部分海区流的空间变率十分显著,如阿古拉斯回流区、马达加斯加北部、南印度洋西部海盆和澳大利亚西侧海区等.特别地,虽然可能受到如季节变化和涡旋扰动等因素的干扰,在漂流浮标拉格朗日式的观测下没有发现显著的副热带逆流,但是可以通过平均动能和涡动能分布观察到逆流的微弱特征.此外,基于浮标示踪,还反推留尼汪岛附近漂流浮标的可能来源,得到其沿南副热带环流的3种移动路径,这对海上搜索具有现实指示意义. Based on historical surface drifting buoy data, the mean-state characteristics of surface subtropical circulation in the South Indian Ocean are analyzed by using the trajectory tracking method. The buoy path shows that the transport of the South Indian Ocean water from high latitudes to low latitudes can be divided into two types: On the east side of the Indian Ocean, it flows northward along the southern equatorial stream and then bypasses the northern side of the island of Madagascar and across the equator to the northern hemisphere across the equator of Africa; or from the central south of the South China Sea to the south by the influence of the southern equatorial stream and then east of Madagascar to return to the South Indian Ocean Subtropical Circulation The velocity and energy results obtained for the drifting buoys show that the spatial variability of some of the sea flows is significant, such as the Agulasian reflow zone, northern Madagascar, the western South Indian Ocean basin and the western Australian coast, etc. In particular, Such as seasonal variations and vortex disturbances, no significant subtropical countercurrent was found under the Lagrangeian drifting buoy, but weak features of the countercurrent can be observed by the average kinetic energy and eddy energy distribution.Furthermore, Labeling also backtracked possible sources of drifting buoys near Reunion Island Which, it has practical implications for maritime search path of movement along three kinds of subtropical gyre of the south.