热带大气30-90天尺度的季节内振荡（MJO）及其与海洋的相互作用对天气和气候都有显著的影响，对它的深入研究将为我国中长期天气预报能力的提升奠定夯实的基础。本项目拟以Dynamics of the Madden-Julian Oscillation（DYNAMO）科学考察和基于观测的再分析资料为基础，结合其它观测数据，通过对MJO和热带印度洋障碍层厚度（BLT）关联的定性和定量探讨，揭示BLT在MJO触发及维持中所扮演的角色，并提出一个基于BLT的MJO机理。同时将不同BLT-MJO条件下的湿度和热量限制运用于Weather Research and Forecasting（WRF）模式的积云对流参数化方案中，调试相应的对流触发条件，研究相关影响，以期提升模式对MJO的模拟能力。本项目研究对完善MJO的物理机制具有重要的理论意义，对我国达成从短期到长期的“无缝天气预报”具有实际应用价值。

As an important tropical system, Madden-Julian Oscillation (MJO) and its relationship with the ocean have a significant impact on the weather and climate, and attract more and more global attention. To explore these, Dynamics of the Madden-Julian Oscillation（DYNAMO）observations, reanalysis-based products, and other observational datasets are used to test the potential impact of tropical Indian Ocean barrier layer’s variety on the initiation and maintenance of MJO. Cloud evolution and moist static energy associated with the MJO life cycle over the tropical Indian Ocean during boreal winter will be discussed under different Ocean Barrier Layer（OBL）situation. A hypothesis about the control exerted by OBLs on the turbulent vertical heat flux at the base of the ocean mixed layer（OML）and consequently the sea surface temperature（SST) , and then the MJO will be established. Different convective trigger conditions identified from the above hypothesis will be explored using Weather Research and Forecasting (WRF) model experiments through the modifications of convection scheme. Overall, the target of our project is to improve medium-long-range forecast, especially the intraseasonal prediction.