The propagation process and characteristics of tropical intraseasonal oscillation (TISO) in Indian Ocean from 1985 to 2017 (from May to October) are investigated using high-resolution satellite data and reanalysis data. There are three types of northward propagation of the TISO in Indian Ocean. The stable type: the convective signal is originated from the south of the equator, in the Western Indian Ocean, then steadily propagates northward to the Indian Peninsula. The attenuated type: it is similar to the stable type in the early stage, but attenuates rapidly after it propagating northward to the Bay of Bengal. The enhanced type: there is no strong convective signal in the early stage, about ten days later, the signal changes from the southern of the Indian Peninsula begin to intensify and developed the Himalayas. During the northward propagation of TISO, convective anomalies are accompanied by easterly shear anomalies, sea surface temperature (SST) anomalies and water vapor disturbances in the boundary layer, which have different effects on the three types of propagation. The positive sea surface temperature anomalies on the north side of convective events will promote the northward propagation of convection, playing a significant role in both stable and attenuated equatorial propagation processes, but the positive SST anomalies is more significant on the south side of the convective event in the enhanced type and inhibits the northward propagation of the convective event. The easterly vertical shear mechanism provides a continuous impetus for the stable propagation of the stable and enhanced types of events, with more significant effects later in the events. The disturbed water vapor in the boundary layer aggravates the instability of the atmosphere and induces the convection system to move northward before and after the stable events, the early attenuation events and the occurrence of the enhanced events. The research results can help improving the accuracy of predicting summer intraseasonal precipitation in Southeast Asia. 

利用高分辨率的卫星资料和再分析资料, 详细地探究1985—2017年夏季(5—10月)热带印度洋季节内振荡(TISO)的北向传播过程和特征。结果表明, 印度洋TISO的北向传播可以分为3类: 稳定型, 对流信号起源于赤道以南, 印度洋西部, 稳定地向北传播至印度半岛北部; 衰减型, 前期与稳定型相似, 但向北传播至孟加拉湾附近后迅速衰减; 增强型, 前期在赤道附近信号较弱, 大约10天后, 对流信号从印度半岛南部开始显著增强, 并发展至喜马拉雅山脉以南。TISO北向传播过程中伴随显著的东风切变异常、海表面温度异常和边界层水汽扰动, 三者在不同类型的北向传播中起不同的作用。对流事件北侧的海温正异常会促进对流的北向传播, 在稳定型和衰减型的赤道传播过程中都起到显著的作用, 增强型传播过程中海温正异常在对流南侧更显著, 会抑制对流的北向传播。东风垂直切变机制为稳定型和增强型的稳定北向传播提供持续的动力, 在事件后期的影响更加显著。边界层水汽扰动的经向不对称性在稳定型事件前后、衰减型事件前期以及增强型事件发生时加剧大气的不稳定性, 诱导对流系统向北移动。研究结果有助于提高东南亚夏季季节内降水预测的准确性。