基于CINDY外场观测数据与模式数值试验的MJO产生机理研究

深入理解热带大气季节内振荡（MJO）的产生机理，对于进行MJO预测至关重要，这需要基于观测数据和气候模式两方面开展研究。其中，观测数据是揭示MJO产生过程的事实基础，数值模式是验证MJO产生机理的重要手段。但受研究方法、资料误差、模式性能等影响，MJO的产生机理尚具争议。本项目拟利用由WCRP/CLIVAR组织发起的热带印度洋外场实验（CINDY2011）期间多套观测数据，并辅之以高分辨率再分析资料，通过水汽、热量和动量的收支诊断，揭示MJO事件产生的前兆信号和物理过程。在此基础上，利用ECHAM模式设计敏感性实验，检验影响MJO产生过程的关键因子及其地理位置和时间尺度，定量比较热带外与热带强迫，以及热带地区上游、下游与局地强迫的相对重要性，从而揭示CINDY2011期间MJO事件的产生机理及其异同之处。通过项目研究，有望为提升MJO初始期信号的监测水平和短期气候的预测能力提供科学依据。

To understand the generation mechanisms of MJO, we need more "realistic" observational data sets and models with better skill on the MJO simulation. The observation is the basic to reveal the generating processes and the model is a method for the generation mechanisms verification. Studies have shown that, influenced by the research method, observational data, model bias and so on, generation mechanisms of MJO is still controversial, the effects from mid-latitude and tropical equatorial modes are both uncertain. To collect more observational data sets, Cooperative Indian Ocean Experiment on Intraseasonal Variability in Year 2011 (CINDY2011) endorsed by WCRP/CLIVAR took place. The aim of the field experiment CINDY2011 is to collect in-situ atmospheric and oceanic data to study the initiation process of MJO over the equatorial Indian Ocean and improve the understanding and the forecast skill of MJO. Through the comparison of multiple observation and reanalysis data sets during CINDY2011, data dependence on features of MJO can be tested firstly. Further, the precursor signal and dynamic/ thermodynamic process of MJO will be revealed by diagnostic analysis. On this basis, sensitivity numerical experiments using the ECHAM are used to discuss the key factors affecting the MJO generation process and comparing the relative importance of extra-tropical, tropical, upstream, downstream and local forcing and the MJO generation mechanisms during will CINDY2011 will be studied. This project will contribute to provide scientific basis for improving MJO monitoring level and short term climate prediction ability.