东北亚夏季降水的年代际变化直观表现为降水空间分布的不均匀性，实质则是海温等强迫下欧亚中纬度环流和水汽输送的热力和动力学作用的不同表现，相关研究对于理解和把握东北亚气候趋势有重要科学意义。项目围绕1990s末东北亚夏季降水的旱涝调整，(1)研究大西洋和北太平洋海温异常对欧亚中纬度环流和水汽输送的热力和动力学作用，重点探讨大西洋多年代际涛动(AMO)和太平洋年代际涛动(PDO)的不同位相配置对环流和水汽输送的影响是否存在“作用效果增强(或减弱)”的协同作用，从新的角度理解东北亚夏季降水年代际调整的物理机制。(2)开展叠加AMO、PDO和ENSO等多个不同区域海温异常的大气模式数值模拟试验；(3)通过对全球耦合模式的客观评估，诊断模式预报中东北亚夏季降水年代际变化的误差成因，研发基于动力-相似理论的模式误差订正新方案，开展1990s末的误差订正试验.

The direct phenomenon of the decadal change of Northeast Asia summer precipitation is its spatial distribution inhomogeneity of precipitation in different periods, however its substance should be the thermodynamic and dynamical behavior of sea surface temperature (SST) forced anomalies of circulation and water vapor transportation in Eurasia. Research in this field is both good for understanding the climate background and estimating the climate trend of Northeast Asia. Focusing on the Decadal Change of Northeast Asia Summer Precipitation in Late 1990s, this research try to analyze its connection to anomalies of circulation and water vapor transportation in Eurasia and related external forces or feedback of Atlantic and North Pacific SST, to reveal its possible 'resonance ' and 'anti-resonance' synergistic action of AMO and PDO to circulation and water vapor transportation in Eurasia. Furthermore, numerical simulation of AMO and PDO related SST anomalies using atmosphere model was implemented for verifying the dynamical and thermodynamic mechanism. The attribution of prediction error of Northeast Asia summer precipitation is also analyzed by evaluating the prediction skill of SST anomalies and related atmosphere respond in the global coupled model for developing a dynamical-analogy skill based prediction error modification scheme. Based on this new scheme, the mechanism of synergistic action of AMO and PDO to the circulation and water vapor transportation in Eurasia is further verified.