海洋性大陆地区季节内振荡与高频运动相互作用机理研究

热带季节内振荡（MJO）为热带大气季节内尺度变化最主要的模态，其对热带的天气和气候变化具有显著影响，深入理解季节内振荡与高频运动相互作用机制是提高延伸期预报能力的关键。本项目拟开展深入而细致的观测资料与多模式资料分析，结合理想数值试验，研究季节内振荡的多尺度相互作用机制。包含三个主要研究内容：1）揭示MJO对高频模态包括日循环，天气尺度运动及赤道波动 (包括开尔文波，西传的重力惯性波，罗斯贝波和混合罗斯贝重力波) 的影响机理。2）揭示高频模态的升尺度反馈对MJO强度，结构和传播的影响。3）对参加MJOTF和GASS多模式比较计划的27个全球环流模式进行系统性诊断，揭示MJO和高频运动的相互作用特征。

The Madden-Julian Oscillation (MJO) is the most prominent mode of intraseasonal variability in the tropics. As it exerts great influences upon the weather and climate systems in tropics, understanding its interaction with higher-frequency motion is a key for improving extended-range weather forecasting. This proposal aims to use both the observational data (including high-resolution reanalysis data) and numerical model experiments to investigate the scale interaction mechanisms related to MJO. This proposal consists of three major tasks: 1）we propose to investigate how MJO modulates higher-frequency waves including the diurnal cycle, synoptic-scale motion and equatorial waves such as equatorial Kelvin waves, Rossby waves, inertial gravity waves and mixed Rossby-gravity waves; 2）we will develop a strategy to reveal how the higher-frequency waves feed back to MJO; 3）we will diagnose the characteristics of MJO-higher frequency motion interaction in 27 GCMs that participated in MJOTF/GASS multi-model intercomparison project.